app_directed_pickup.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Joshua Colp
 *
 * Joshua Colp <[email protected]>
 *
 * Portions merged from app_pickupchan, which was
 * Copyright (C) 2008, Gary Cook
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Directed Call Pickup Support
 *
 * \author Joshua Colp <[email protected]>
 * \author Gary Cook
 *
 * \ingroup applications
 */

/*** MODULEINFO
 <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/app.h"
#include "asterisk/pickup.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"

#define PICKUPMARK "PICKUPMARK"

/*** DOCUMENTATION
 <application name="Pickup" language="en_US">
 <synopsis>
 Directed extension call pickup.
 </synopsis>
 <syntax>
 <parameter name="targets" argsep="&amp;">
 <argument name="extension" argsep="@" required="true">
 <para>Specification of the pickup target.</para>
 <argument name="extension" required="true"/>
 <argument name="context" />
 </argument>
 <argument name="extension2" argsep="@" multiple="true">
 <para>Additional specifications of pickup targets.</para>
 <argument name="extension2" required="true"/>
 <argument name="context2"/>
 </argument>
 </parameter>
 </syntax>
 <description>
 <para>This application can pickup a specified ringing channel. The channel
 to pickup can be specified in the following ways.</para>
 <para>1) If no <replaceable>extension</replaceable> targets are specified,
 the application will pickup a channel matching the pickup group of the
 requesting channel.</para>
 <para>2) If the <replaceable>extension</replaceable> is specified with a
 <replaceable>context</replaceable> of the special string
 <literal>PICKUPMARK</literal> (for example 10@PICKUPMARK), the application
 will pickup a channel which has defined the channel variable
 <variable>PICKUPMARK</variable> with the same value as
 <replaceable>extension</replaceable> (in this example,
 <literal>10</literal>).</para>
 <para>3) If the <replaceable>extension</replaceable> is specified
 with or without a <replaceable>context</replaceable>, the channel with a
 matching <replaceable>extension</replaceable> and <replaceable>context</replaceable>
 will be picked up. If no <replaceable>context</replaceable> is specified,
 the current context will be used.</para>
 <note><para>The <replaceable>extension</replaceable> is typically set on
 matching channels by the dial application that created the channel. The
 <replaceable>context</replaceable> is set on matching channels by the
 channel driver for the device.</para></note>
 </description>
 </application>
 <application name="PickupChan" language="en_US">
 <synopsis>
 Pickup a ringing channel.
 </synopsis>
 <syntax >
 <parameter name="channel" argsep="&amp;" required="true">
 <argument name="channel" required="true" />
 <argument name="channel2" required="false" multiple="true" />
 <para>List of channel names or channel uniqueids to pickup if ringing.
 For example, a channel name could be <literal>SIP/bob</literal> or
 <literal>SIP/bob-00000000</literal> to find
 <literal>SIP/bob-00000000</literal>.
 </para>
 </parameter>
 <parameter name="options" required="false">
 <optionlist>
 <option name="p">
 <para>Supplied channel names are prefixes. For example,
 <literal>SIP/bob</literal> will match
 <literal>SIP/bob-00000000</literal> and
 <literal>SIP/bobby-00000000</literal>.
 </para>
 </option>
 </optionlist>
 </parameter>
 </syntax>
 <description>
 <para>Pickup a specified <replaceable>channel</replaceable> if ringing.</para>
 </description>
 </application>
 ***/

static const char app[] = "Pickup";
static const char app2[] = "PickupChan";

struct pickup_by_name_args {
 /*! Channel attempting to pickup a call. */
 struct ast_channel *chan;
 /*! Channel uniqueid or partial channel name to match. */
 const char *name;
 /*! Length of partial channel name to match. */
 size_t len;
};

static int find_by_name(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *target = obj;/*!< Potential pickup target */
 struct pickup_by_name_args *args = data;

 if (args->chan == target) {
 /* The channel attempting to pickup a call cannot pickup itself. */
 return 0;
 }

 ast_channel_lock(target);
 if (!strncasecmp(ast_channel_name(target), args->name, args->len)
 && ast_can_pickup(target)) {
 /* Return with the channel still locked on purpose */
 return CMP_MATCH | CMP_STOP;
 }
 ast_channel_unlock(target);

 return 0;
}

static int find_by_uniqueid(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *target = obj;/*!< Potential pickup target */
 struct pickup_by_name_args *args = data;

 if (args->chan == target) {
 /* The channel attempting to pickup a call cannot pickup itself. */
 return 0;
 }

 ast_channel_lock(target);
 if (!strcasecmp(ast_channel_uniqueid(target), args->name)
 && ast_can_pickup(target)) {
 /* Return with the channel still locked on purpose */
 return CMP_MATCH | CMP_STOP;
 }
 ast_channel_unlock(target);

 return 0;
}

/*! \brief Helper Function to walk through ALL channels checking NAME and STATE */
static struct ast_channel *find_by_channel(struct ast_channel *chan, const char *channame)
{
 struct ast_channel *target;
 char *chkchan;
 struct pickup_by_name_args pickup_args;

 pickup_args.chan = chan;

 if (strchr(channame, '-')) {
 /*
 * Use the given channel name string as-is. This allows a full channel
 * name with a typical sequence number to be used as well as still
 * allowing the odd partial channel name that has a '-' in it to still
 * work, i.e. Local/bob@en-phone.
 */
 pickup_args.len = strlen(channame);
 pickup_args.name = channame;
 } else {
 /*
 * Append a '-' for the comparison so we check the channel name less
 * a sequence number, i.e Find SIP/bob- and not SIP/bobby.
 */
 pickup_args.len = strlen(channame) + 1;
 chkchan = ast_alloca(pickup_args.len + 1);
 strcpy(chkchan, channame);/* Safe */
 strcat(chkchan, "-");
 pickup_args.name = chkchan;
 }
 target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
 if (target) {
 return target;
 }

 /* Now try a search for uniqueid. */
 pickup_args.name = channame;
 pickup_args.len = 0;
 return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
}

/*! \brief Attempt to pick up named channel. */
static int pickup_by_channel(struct ast_channel *chan, const char *name)
{
 int res = -1;
 struct ast_channel *target;/*!< Potential pickup target */

 /* The found channel is already locked. */
 target = find_by_channel(chan, name);
 if (target) {
 res = ast_do_pickup(chan, target);
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 return res;
}

/* Attempt to pick up specified extension with context */
static int pickup_by_exten(struct ast_channel *chan, const char *exten, const char *context)
{
 struct ast_channel *target = NULL;/*!< Potential pickup target */
 struct ast_channel_iterator *iter;
 int res = -1;

 if (!(iter = ast_channel_iterator_by_exten_new(exten, context))) {
 return -1;
 }

 while ((target = ast_channel_iterator_next(iter))) {
 ast_channel_lock(target);
 if ((chan != target) && ast_can_pickup(target)) {
 ast_log(LOG_NOTICE, "%s pickup by %s\n", ast_channel_name(target), ast_channel_name(chan));
 break;
 }
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 ast_channel_iterator_destroy(iter);

 if (target) {
 res = ast_do_pickup(chan, target);
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 return res;
}

static int find_by_mark(void *obj, void *arg, void *data, int flags)
{
 struct ast_channel *target = obj;/*!< Potential pickup target */
 struct ast_channel *chan = arg;
 const char *mark = data;
 const char *tmp;

 if (chan == target) {
 /* The channel attempting to pickup a call cannot pickup itself. */
 return 0;
 }

 ast_channel_lock(target);
 tmp = pbx_builtin_getvar_helper(target, PICKUPMARK);
 if (tmp && !strcasecmp(tmp, mark) && ast_can_pickup(target)) {
 /* Return with the channel still locked on purpose */
 return CMP_MATCH | CMP_STOP;
 }
 ast_channel_unlock(target);

 return 0;
}

/* Attempt to pick up specified mark */
static int pickup_by_mark(struct ast_channel *chan, const char *mark)
{
 struct ast_channel *target;/*!< Potential pickup target */
 int res = -1;

 /* The found channel is already locked. */
 target = ast_channel_callback(find_by_mark, chan, (char *) mark, 0);
 if (target) {
 res = ast_do_pickup(chan, target);
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 return res;
}

static int pickup_by_group(struct ast_channel *chan)
{
 struct ast_channel *target;/*!< Potential pickup target */
 int res = -1;

 /* The found channel is already locked. */
 target = ast_pickup_find_by_group(chan);
 if (target) {
 ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));
 res = ast_do_pickup(chan, target);
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 return res;
}

/* application entry point for Pickup() */
static int pickup_exec(struct ast_channel *chan, const char *data)
{
 char *parse;
 char *exten;
 char *context;

 if (ast_strlen_zero(data)) {
 return pickup_by_group(chan) ? 0 : -1;
 }

 /* Parse extension (and context if there) */
 parse = ast_strdupa(data);
 for (;;) {
 if (ast_strlen_zero(parse)) {
 break;
 }
 exten = strsep(&parse, "&");
 if (ast_strlen_zero(exten)) {
 continue;
 }

 context = strchr(exten, '@');
 if (context) {
 *context++ = '\0';
 }
 if (!ast_strlen_zero(context) && !strcasecmp(context, PICKUPMARK)) {
 if (!pickup_by_mark(chan, exten)) {
 /* Pickup successful. Stop the dialplan this channel is a zombie. */
 return -1;
 }
 } else {
 if (ast_strlen_zero(context)) {
 context = (char *) ast_channel_context(chan);
 }
 if (!pickup_by_exten(chan, exten, context)) {
 /* Pickup successful. Stop the dialplan this channel is a zombie. */
 return -1;
 }
 }
 ast_log(LOG_NOTICE, "No target channel found for %s@%s.\n", exten, context);
 }

 /* Pickup failed. Keep going in the dialplan. */
 return 0;
}

/* Find channel for pick up specified by partial channel name */
static struct ast_channel *find_by_part(struct ast_channel *chan, const char *part)
{
 struct ast_channel *target;
 struct pickup_by_name_args pickup_args;

 pickup_args.chan = chan;

 /* Try a partial channel name search. */
 pickup_args.name = part;
 pickup_args.len = strlen(part);
 target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
 if (target) {
 return target;
 }

 /* Now try a search for uniqueid. */
 pickup_args.name = part;
 pickup_args.len = 0;
 return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
}

/* Attempt to pick up specified by partial channel name */
static int pickup_by_part(struct ast_channel *chan, const char *part)
{
 struct ast_channel *target;/*!< Potential pickup target */
 int res = -1;

 /* The found channel is already locked. */
 target = find_by_part(chan, part);
 if (target) {
 res = ast_do_pickup(chan, target);
 ast_channel_unlock(target);
 target = ast_channel_unref(target);
 }

 return res;
}

enum OPT_PICKUPCHAN_FLAGS {
 OPT_PICKUPCHAN_PARTIAL = (1 << 0), /* Channel name is a partial name. */
};

AST_APP_OPTIONS(pickupchan_opts, BEGIN_OPTIONS
 AST_APP_OPTION('p', OPT_PICKUPCHAN_PARTIAL),
END_OPTIONS);

/* application entry point for PickupChan() */
static int pickupchan_exec(struct ast_channel *chan, const char *data)
{
 char *pickup = NULL;
 char *parse = ast_strdupa(data);
 AST_DECLARE_APP_ARGS(args,
 AST_APP_ARG(channel);
 AST_APP_ARG(options);
 AST_APP_ARG(other); /* Any remining unused arguments */
 );
 struct ast_flags opts;

 AST_STANDARD_APP_ARGS(args, parse);

 if (ast_strlen_zero(args.channel)) {
 ast_log(LOG_WARNING, "PickupChan requires an argument (channel)!\n");
 /* Pickup failed. Keep going in the dialplan. */
 return 0;
 }
 if (ast_app_parse_options(pickupchan_opts, &opts, NULL, args.options)) {
 /*
 * General invalid option syntax.
 * Pickup failed. Keep going in the dialplan.
 */
 return 0;
 }

 /* Parse channel */
 for (;;) {
 if (ast_strlen_zero(args.channel)) {
 break;
 }
 pickup = strsep(&args.channel, "&");
 if (ast_strlen_zero(pickup)) {
 continue;
 }

 if (ast_test_flag(&opts, OPT_PICKUPCHAN_PARTIAL)) {
 if (!pickup_by_part(chan, pickup)) {
 /* Pickup successful. Stop the dialplan this channel is a zombie. */
 return -1;
 }
 } else if (!pickup_by_channel(chan, pickup)) {
 /* Pickup successful. Stop the dialplan this channel is a zombie. */
 return -1;
 }
 ast_log(LOG_NOTICE, "No target channel found for %s.\n", pickup);
 }

 /* Pickup failed. Keep going in the dialplan. */
 return 0;
}

static int unload_module(void)
{
 int res;

 res = ast_unregister_application(app);
 res |= ast_unregister_application(app2);

 return res;
}

static int load_module(void)
{
 int res;

 res = ast_register_application_xml(app, pickup_exec);
 res |= ast_register_application_xml(app2, pickupchan_exec);

 return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Directed Call Pickup Application");